He attended Bethel Park High School, where he excelled in academics.[7] He joined the National Technical Honor Society in 2021 while a junior in high school.[8] In 2022, he graduated with high honors and won a $500 "star award" from the National Math and Science Initiative.[9][10][11]

Classmates and school officials characterized him as quiet, with classmates saying he was often bullied for various reasons,[1][2][10] including his quiet demeanor, body odor, and for wearing camouflage hunting outfits and surgical masks to school.[1][12][13]According to the school district, detailed records of disciplinary incidents including bullying and threats do not contain any with Crooks playing a part. The school district concludes "The assailant was known as a quiet, bright young man who generally got along with his teachers and classmates."[14]

Crooks enjoyed playing chess and video games and was learning computer programming.[10][15][16] He attended a computer technology program at the Steel Center for Career and Technical Education.[8] Some students and graduates from Bethel Park High School alleged that Crooks tried out for his school's rifle team, but he failed the tryout because of his poor aim. The Bethel Park School District said there is no record of Crooks trying out for the team.[17][18]

Crooks earned an associate degree in engineering science from the Community College of Allegheny County, graduating two months before the shooting. He was employed as a dietary aide in a local nursing home at the time of the shooting.[4][15][18][19] According to the nursing home, he had passed a background check and "performed his job without concern".[20] He had been accepted into both the University of Pittsburgh and Robert Morris University and planned to attend the latter.[20][21]